Directly engaged syringe driver system

Abstract

A syringe driver system comprises a rotatable threaded lead screw shaft and a plunger which directly engages the threaded shaft such that rotation of the shaft drives the plunger into the syringe body. The plunger is formed with a threaded shaft engaging portion in the form of a half nut to engage with and follow the threaded shaft. The syringe driver system further comprises a guide system to secure the plunger in direct engagement with the threaded shaft and to prevent rotation of the plunger. An arm of the plunger stem carries markers useful in determining the near end of infusion. The syringe body carries a marker or markers useful in determining a characteristic about the syringe, such as its volume.

What is claimed is: 
     
       1. A syringe for use in a fluid delivery apparatus having a threaded shaft, said syringe comprising:
 a syringe body; 
 a plunger stem having a distal end and a proximal end; 
 a stopper positioned at the distal end of the stem, the stopper sized to fit within the syringe body; and 
 a flange positioned at the proximal end of the stem and outside of the syringe body, the flange extending radially outwardly from the stem and having a threaded portion sized to engage the threaded shaft, wherein the flange has radially outwardly facing edges, the threaded portion being adjacent the edges, the edges formed to guide the threaded portion onto the threaded shaft; 
 wherein the plunger stem comprises an open area in the area extending from the threaded portion to the stopper to receive the threaded shaft. 
 
     
     
       2. The syringe of  claim 1  wherein the threaded portion is molded into the flange. 
     
     
       3. The syringe of  claim 1  wherein a guide slot is provided on the plunger substantially opposite the threaded portion, the guide slot configured to receive a guide rail to securely seat the threaded portion on the threaded shaft. 
     
     
       4. The syringe of  claim 1  wherein the plunger stem comprises a plurality of markers adapted to indicate the movement and position of the plunger within the syringe body. 
     
     
       5. The syringe of  claim 4  wherein the plurality of markers comprise a linear grid. 
     
     
       6. The syringe of  claim 4  wherein an area of the plunger between the markers is substantially opaque and the markers comprise substantially transparent portions. 
     
     
       7. The syringe of  claim 1  wherein the plunger includes a marker indicative of the position of the plunger, the marker mounted so as to move with the plunger. 
     
     
       8. The syringe of  claim 1  wherein the syringe body includes a syringe identification marker indicative of a characteristic of the syringe; and
 the system further comprising a syringe detection system including a detector for detecting the identification marking of the syringe, the syringe detector system adapted to provide a signal in accordance with the identification marking detected. 
 
     
     
       9. The syringe of  claim 1  wherein the flange includes a cut-out within which the threaded portion is disposed and the edges of the flange flare away from the cut-out to give the cut-out a non-clamping rounded V-shape wherein the V-shape guides the flange over the threaded shaft to engage the threaded portion with the threaded shaft but does not exert a clamping force to the threaded shaft. 
     
     
       10. A syringe for use in a fluid delivery apparatus having a threaded shaft, said syringe comprising:
 a syringe body;
 a plunger stem having a distal end and a proximal end; 
 
 a stopper positioned at the distal end of the stem, the stopper sized to fit within the syringe body; and 
 a flange positioned at the proximal end of the stem and outside of the syringe body, the flange extending radially outwardly from the stem, the flange having a thread facing outwardly, the thread sized to engage the threaded shaft, wherein the flange includes a cut-out within which the thread is disposed, the flange having edges that flare away from the cut-out to give the cut-out a non-clamping rounded V-shape wherein the V-shape guides the flange over the threaded shaft to engage the thread with the threaded shaft but does not exert a clamping force to the threaded shaft; 
 wherein a guide slot is provided on the plunger substantially opposite the thread, the guide slot configured to receive a guide rail to securely seat the thread on the threaded shaft. 
 
     
     
       11. The syringe of  claim 10  wherein the thread is molded into the flange. 
     
     
       12. The syringe of  claim 10  wherein the plunger stem comprises an open area in the area extending from the thread to the stopper to receive the threaded shaft. 
     
     
       13. The syringe of  claim 10  wherein the plunger comprises a plurality of markers adapted to indicate the movement and position of the plunger within the syringe body. 
     
     
       14. The syringe of  claim 13  wherein the plurality of markers comprise a linear grid. 
     
     
       15. The syringe of  claim 13  wherein an area of the plunger between the markers is substantially opaque and the markers comprise substantially transparent portions. 
     
     
       16. The syringe of  claim 10  wherein the plunger includes a marker indicative of the position of the plunger, the marker mounted so as to move with the plunger. 
     
     
       17. The syringe of  claim 10  wherein the syringe includes a syringe identification marker indicative of a characteristic of the syringe. 
     
     
       18. A syringe for use in a fluid delivery apparatus having a threaded shaft, said syringe comprising:
 a syringe body; 
 a plunger stem having a distal end and a proximal end; 
 a stopper positioned at the distal end of the stem, the stopper sized to fit within the syringe body; and 
 a flange positioned at the proximal end of the stem and outside of the syringe body, the flange comprising radially outwardly facing edges and a threaded portion adjacent the edges, the threaded portion sized to engage the threaded shaft, wherein the flange includes a cut-out within which the threaded portion is disposed and edges of the flange flare away from the cut-out to give the cut-out a non-clamping rounded V-shape wherein the V-shape guides the flange over the threaded shaft to engage the threaded portion with the threaded shaft but does not exert a clamping force to the threaded shaft; 
 wherein the plunger stem comprises an open area in the area extending from the threaded portion to the stopper to receive the threaded shaft. 
 
     
     
       19. The syringe of  claim 18  wherein the threaded portion is molded into the flange. 
     
     
       20. The syringe of  claim 18  wherein a guide slot is provided on the plunger substantially opposite the threaded portion, the guide slot configured to receive a guide rail to securely seat the threaded portion of the flange on the threaded shaft. 
     
     
       21. The syringe of  claim 18  wherein the plunger comprises a plurality of markers adapted to indicate the movement and position of the plunger within the syringe body. 
     
     
       22. The syringe of  claim 21  wherein the plurality of markers comprise a linear grid. 
     
     
       23. The syringe of  claim 21  wherein an area of the plunger between the markers is substantially opaque and the markers comprise substantially transparent portions. 
     
     
       24. The syringe of  claim 18  wherein the plunger includes a marker indicative of the position of the plunger, the marker mounted so as to move with the plunger. 
     
     
       25. The syringe of  claim 18  wherein the syringe includes a syringe identification marker indicative of a characteristic of the syringe.